Just say "sig" and "ur" like two separate words but quickly and "rós" is very similar to the English word "rose", nearly said in the same way except in English the emphasis is on the "o" but in Icelandic the emphasis of the word is on the "s" in the end, in the same way if there is any emphasis at all on any specific letter in "sigur" it would be on the "r" in the end.